Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us





The birth of mibolerone

We came across this when wasting valuable time in the archives of our favourite journal: the article in which researchers at Upjohn announced to the world their research on 7-methyl nandrolone analogues.

Upjohn had been interested in these substances since the company discovered how effective 7-methyl testosterone and its analogues were. Upjohn had plans in the sixties to launch one of these, 7-alpha,17-alpha-dimethyl testosterone, under the name of Myagen on the market. Myagen was thirteen times as anabolic as methyl testosterone and three times as androgenic.

But things could be even better, the article suggested.

In the figure below SQ(X_TP) represents the effects of injections. The effects are compared with those of testosterone propionate. The table compares the oral effect of the steroids with that of methyl testosterone.

The birth of mibolerone

7alpa-methyl nandrolone is what we now know as MENT. Researchers regard MENT as a potential contraceptive for men.

Upjohn researchers noticed that MENT-acetate, in the figure above, is eliminated really quickly from the body. For this reason the company made a longer-lasting MENT ester: a cyclopentylpropionate. This was five times as powerful as testosterone cyclopentylpropionate, according to the article.

The birth of mibolerone
But the researchers were most impressed by the oral effect of 7alpha,17 alpha-dimethyl 19-nortestosterone, they said. This steroid, later marketed as mibolerone, proved to be 18 times as androgenic and 41 times as anabolic as methyl testosterone in animal tests.

Mibolerone is toxic to the liver possibly even more toxic than Upjohn's Myagen, which was taken off the market for this reason. Mibolerone is intended for domestic pets and not for humans, and is used to suppress ovulation.

According to Duchaine's Underground Steroid Handbook, mibolerone has made its way into strength sports. Power lifters use it because it increases aggression.

Occasionally mibolerone is mentioned on message boards. Rumour has it that the underground steroids lab Supra started producing it in 2004. [ 29-Mar-2004] [ 24-11-2004]

The same boards also suggest that mibolerone is found in the world of dogfights. [ 11-05-2005] The dogs are given the steroid to make them aggressive.

Wrestlers and boxers use mibolerone to achieve the same effect, according to the stories on the boards. "Supposedly these are what Mike Tyson was taking when he bit off Holyfields ear".

Steroids Volume 1, Issue 3, March 1963, Pages 317-324.